Treatment of subdivided ores for agglomerating or reducing them and apparatus therefor.



e. GRUNDAL & H. NILSSON.

TREATMENT OF SUBDIVIDED ORES FOR AGGLOMERATING 0R REDUCING THEM AND APPARATUS THEREFOR.

Patented June 8, 1915.

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3 E M M W5 1 26 GUSTAF GRQNDAL, 0F DJ'URSHOLM, AND HERMAN NILSSOZN', 0F NYHAMMAR, SWEDEN.

TREATMENT OF SUBDIVIDED ORES FOR AGGLOMERATING OR REDUCING THEM AND APPARATUS THEREFOR.

Specification of Letters Patent.

Patented June 8, 19115.

Application filed May 23, 1914. Serial No. 840,549.

To all whom it may concern Be it known that we, GUsTAr GRoNnAL, a subject of the King of Sweden, and resident of Djursholm, Sweden, and HERMAN NILssoN, a subject of the Kin of Sweden, and resident of Nyhammar, -foweden, have mvented certain new and useful Improved Treatment of Subdivided Ores for Agglomerating or Reducing Them and Apparatus Therefor, of which the following is a specification.

This invention relates to a method of agglomerating subdivided or pulverulent ores, more particularly iron ore, into the form of hard porous lumps or lumps of metal, and also relates to a furnace for carrying out this method.

The subdivided or pulverulent ore is moistened to a suitable extent and packed into ironreceptacles of any suitable shape for instance slightly conical, having both ends open. During this packing or after the packing the mass of ore is provided with longitudinal channels or passages through it. The receptacles are arranged abutting against each other in a long vertical, inclined or horizontal series against a suitable fire place or burner and the combustion products either oxidizing, inert or reducing, as required, are led through the channels in the whole series or furnace. As soon as the ore in the foremost receptacle is brought into the desired state, this receptacle is removed, the remaining receptacles are moved toward the burner and another" receptacle filled with fresh ore in the manner specified is inserted at the end of the furnace, and so on during the process. It is advantageous to place the removed receptacle with the mass still hot on the other side of the burner and to pass the air for the combustion through it, thereby heating theair and cooling the mass.

If the series of receptacles is horizontal or nearly so, "fire-place receptacles or burners may be inserted at suitable places in the series or furnace. These fire-place receptacles or burners have the same shape as the other receptacles or any similar shape and each of them .is provided with a fire-proof lining and a side opening, preferably a projecting short tube, capable of being closed.

After the heating of the furnace'air under pressure is made to enter one end of the furnace and combustible gas or any suitable combustible, such as powdered coal, is fed through the short tube into one of the fireplace receptacles. In this receptacle, the burner, the combustion is efiected and the products of combustion sweep through the channels in the ore mass in that part of the furnace lying on the other side of this burner, escaping at the other end of the furnace through a chimney. A form of such a furnace is shown, by Way of example, in the accompanying drawing.

Figure l is a longitudinal section through the furnace. Fig. 2 a cross section on line 22 of Fig. 1 and Figs. 3 and 4 cross sections on lines 33 and 4-4 respectively of Fig. 1.

A represents a set of receptacles b mounted on wheels and having the mass 0 of ore packed or stamped into them and provided with longitudinal channels or passages d. B, C and D are other such sets of receptacles.

E, E E are fire-place receptacles with openings closed by covers 9.

E and t are fire-place receptacles at the ends of the furnace, that is to say at the ends of the assembled receptacles. Each of the receptacles has trunnions h to permit of its mampulation before and after assemblage.

i is a blast pipe adapted to fit substantially tightly to the mouth of the receptacle E by means of a funnel shaped enlargement 7c. The lower portion of this pipe is arranged pivotally like a folding funnel of a steamboat so that it may be turned aside when required.

Z is a pipe for gaseous fuel adapted to be fitted t0 and removed from the opening 1 of the fire-place next after the first set of receptacles when desired.

m is the chimney having a funnel-shaped enlargement n at its lower end to be placed above the opening f of the fire-place receptacle Et 0 is a plate or door for closing the last receptacle in the series.

In practising the method the fire-place receptacle E is connected with the gas pipe Z and the openings 7 of the fire-place receptaeles E, E and E are closed by the covers 9. The pipe 71 is connected with any suitable blowing engine. During the process the ore 1n set is beingdried while that in sets C and B 1s being hated and reduced and that in set A 1s bemg oxidized and cooled, there by heating the blast. When the operation has been continued until the mass in the receptacles of the set B is sufficiently reduced and heated, the blast as well as the gas is shut off and the pipes 11 and Z are turned aside. The whole series of receptacles, that is the whole furnace, is then moved forward, receptacle after receptacle, so far that the fire-place receptacle E takes the place of the burner E after which this receptacle in turn is connected with the fuel pipe Z. The set A is removed and another set of receptacl s containing fresh ore is inserted at the entrance end of the furnace in substitution for the set D carried forward. Another fireplace receptacle is then brought below the chimney m and the door 0 placed in position.

As mentioned above one fire-place or burner may be used for the whole series of receptacles filled with ore, especially if it is desired to convert the smalls or powdered ore into hard porous lumps. For this purpose the set of receptacles A represented on the drawing may be used alone if the pipe I is connected with the burner E. In this case the set of receptacles A may also be arranged in a vertical or inclined position,

and when the receptacle nearest to the burner with its finished contents is to be removed the other receptacles are first elevated and then lowered toward the burner and another receptacle is placed at the top of the series. The removed receptacle with its heated contents is placed in the air conduit to the burner to preheat the air.

From what has been said above it will be seen that the air for combustion cools the ore contained in the set A before this air, well pre-heated, enters the burner E, andit will further be seen that the combustion products escaping from this burner have a good opportunity of delivering their heat to the mass contained in the receptacles on the other side of the burner E. As the air for combustion passes through the heated body of ore in the set A, the ore, iron ore, is vigorously oxidized, which highly contributes to bring the mass of ore into the form of lumps since at a sufliciently high temperature crystalline ferric oxid is formed.

By an admixture of a small percentage of coal dust to the iron ore and by regulating the blast in such a manner that the combustion productshave a compositionnot preventin the reduction of the ore to ferrous oxid, e0, the ore in the set B can be reduced to this oxid, at least partially. If then the ore containing a high percentage of ferrous oxid is brought into contact with heated air in the cooling compartment A 'a vigorous combustion to ferric oxid occurs, by which the temperature is raised to a considerable extent. Supposing the receptacles B containing the ore mixture reduced to ferrous oxid become the cooling receptacles when the temperature of the ore is.800-900 C. and that here the ore is brought into contact with air at about 500600 G. there arises by the combustion of the ferrous oxid to ferric oxid a temperature sufliciently high for obtaining quite solid briquets or lumps. This being what may be termed an internal combustion the heat is utilized much more effectively than according to other hitherto known methods and the iron receptacles do not become superheated. As seen, in this method the ore and the walls of the furnace are moved together. When it is de sired to reduce an ore completely to a metal, the gas and air must change places, that is combustible gas is to be fed through pipe 73 and air through pipe Z. The method is otherwise the same as that described above, with the exception that a greater proportion of carbon must be added to the ore from the beginning.

It is advantageous that all the sets consist of the same number of receptacles, but this is not absolutely necessary. If, however, the number of receptacles in the sets varies the air pipes as well as the gas pipes have to be arranged to be movable.

In the combustion products escaping through thechimney there is generally still a quantity of un-burnt fuel and this may be utilized for the drying if a sufiicient amount of air is fed through the opening 7 into the last or one of the last fire-place receptacles before the chimney.

We claim 1. A method of treating subdivided or pulverulent ore consisting in packing the ore, in a moistened state into an iron recep- .tacle open at both ends, providing longitudinal channels in the ore, arranging a number of such filled receptacles in series adding thereto a suitable fire-place, passing the combustion products through the said channels until the ore in the receptacle lying next to the fire-place is brought to the de- 1 sired state, afterward removing this receptacle containing the ore and placing it on the other side of the fire-place to be traversed by the air for combustion moving the series of remaining receptacles toward the fire-place and placing another receptacle filled with fresh ore at the other end of the series, and so on, substantially as described.

2. A method of treating subdivided or pulverulent ore consisting in packing the ore, in a moistened state and mixed with a reducing agent, into an iron receptacle open at both ends, providing longitudinal channels in the ore, arranging a number of such filled receptacles in series adding thereto a suitable fire-place, passing the combustion products through the said channels until the ore in the receptacle lying next to the fire-place is brought to the desired state, afterward removing this receptacle 0011- taining the ore and placing it on the other side of the fire-place to-be traversed by the air for combustion moving the series of remaining receptacles toward the fire-place and placing another receptacle filled with fresh ore at the other end of the series, and so on, substantially as described.

3. A method of treating. subdivided or pulverulent ore consisting in packing the ore, in a .moistened state, into an iron receptacle open at both ends, providing longitudinal channels in the ore, arranging a number of such filled receptacles in a horizontal series adding thereto a suitable fireplace, passing the combustion products through the said channels-until the ore in the receptacle lying next to the fire-place is brought to the desired state, afterward removing this receptacle containing the ore and placing it on the other side of the fireplace to be traversed by the air for combustion moving the series of remaining receptacles toward the fire-place and placing another receptacle filled with fresh ore at the other end of the series, and so on, substantially as described.

4. A furnace for treating subdivided or pulverulent ore comprising a series of movable iron receptacles a pted to receive a perforated packed mass of ore and abutting against each other, fire-place receptacles having openings inserted at suitable places in the series, removable lids for normally closing said openings, a .pipe for suitable fuel adapted to be connected with one of the fire-place receptacles through its opening, a

pipe for air under pressure provided-at the delivery end of the furnace, and-a chimney at the other end of the furnace, for carrying off the products of combustion and means for displacing the receptacles during the process, substantially as described.

5. A furnace for treating subdivided or pulverulent ore comprising a horizontal series of movable iron receptacles adapted to receive a perforated packed mass of ore and abutting against each other, fire-place receptacles having openings inserted at suit-.

able places in the series, removable lids for normally closing said openings, a pipe for combustible gas adapted to be connected with one of the fire-place receptacles through its opening, a pipe for air under pressure provided at the delivery end of the furnace, and a chimney at the other end of the furnace, for carrying off the products of combustion and wheels under the receptacles for displacing them during the process, substantially as described.

combustion and means for displacing the receptacles during the process, substantially as described.

7. A furnace for treating subdivided 0r, pulverulent ore comprising a horizontal series of movable iron receptacles adapted to receive a perforated packed mass of ore and reducing agents and abutting against each other, fire-place receptacles having openings inserted at suitable places in the serles,

removable lids for normally closing said openings, a pipe for suitable fuel adapted to be connected with one of the fire-place receptacles through its opening, a pipe for air under pressure provided at the delivery end of the furnace, and a chimney at the other end of the furnace, for carrying olf' the products of combustion and means for displacing the receptacles during the process, substantially as described.

8. A furnace for treating subdivided or pulverulent ore comprising a horizontal series of movable iron receptacles adapted to receive a perforated packed mass of ore and reducing agents and abutting against each other, fire-place receptacles having openings inserted at suitable places in the series, removable lids for normally closing said openings, a pipe for air under pressure adapted to be connected with one of the fire-place receptacles through its opening, a pipe for. suitable fuel provided at the delivery end of the furnace, and a chimney at the other end of the furnace, for carrying ofi the products of combustion and means for displacing the receptacles during the process, substantially as described. In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses. v

GUSTAF GRONDAL. HERM. NILSSON. Witnesses: JACOB .BAGGE,

C. BRODEN. 

